Subsequent Events	3 Months Ended
Subsequent Events	Mar. 31, 2020
Subsequent Events [Abstract]
Subsequent Events	Subsequent Events Financing Arrangements On April 21, 2020, Western Asset Mortgage Capital Corporation (the “Company”) entered into amendments with respect to certain of its loan warehouse facilities. These amendments mainly served to convert an existing residential whole loan facility into a term facility by removing any mark to market margin requirements, and to consolidate the Company’s Non-Qualified Mortgage loans, which were previously financed by three separate, unaffiliated counterparties, into a single facility. The target advance rate under the amended and restated facility will be approximately 84% of the aggregate unpaid principal balance of the loans. The term of the facility is 18 months from the date of the amendment and all principal payments and income generated by the loans during the term of the facility will be used to incrementally repay all obligations thereunder. Upon the securitization or sale by the Company of any whole loan subject to this amended and restated facility, the counterparty will be entitled to receive an exit fee of 0.50% as well as 30% of all realized and projected cash flow on any whole loans above such counterparty’s amortized basis. The counterparty will have full recourse to the Company and any relevant subsidiary for obligations incurred under this amended and restated whole loan facility. Amendments were also effected to the existing residential whole loan facility and two other facilities held by the same counterparty group to provide such group with cross-collateralization and cross-default benefits across these three facilities. Upon any default, income from loans sold under any of these three facilities will be applied to repay obligations incurred under all three facilities, in an agreed-upon order of priority. The amendments also provide for a uniform set of financial covenants with respect to equity, leverage and liquidity requirements across the three facilities held by this counterparty group. The Company’s aggregate borrowings from this counterparty group with respect to its residential whole loans are approximately $385 million and the market value of such loans is approximately $430 million. On May 4, 2020, the Company supplemented one of its existing securities repurchase facilities to confirm terms pursuant to which it will consolidate most of its CMBS and RMBS assets, which are currently financed by multiple counterparties, into a single term facility with limited mark to market margin requirements, as described below. Pursuant to this confirmation, a margin deficit will not occur until such time as the loan to value ratio surpasses a certain threshold (the “LTV Trigger”), on a weighted average basis per asset type, calculated on a portfolio level. If this threshold is reached, the Company may elect to provide cash margin or sell certain assets to the extent necessary to lower the ratio. The term of this facility is 12 months, subject to extensions at the counterparty’s option. All interest income generated by the assets during the term of the facility will be paid to the Company no less often than monthly, with a price differential based on three-month LIBOR plus 5.00% payable to the counterparty quarterly in arrears. Half of all income generated by principal repayments on the underlying assets will be applied to repay the obligations owed to the counterparty, with the remainder paid to the Company, unless the LTV Trigger has occurred, in which case all principal payments will be applied to repay the obligations. The counterparty has a right of first refusal upon any repurchase by the Company of any asset subject to this confirmation, provided the Company may request the counterparty to solicit third party dealer bids with respect to such sale. All asset sale proceeds less 50% of any excess proceeds over the counterparty’s amortized basis will be applied to repay the obligations owed to the counterparty, with the remainder paid to the Company, unless the LTV Trigger has occurred, in which case all asset sale proceeds will be applied to repay the obligations. Customary bank financing breakage fees are also payable upon the sale of the underlying assets. The confirmation also provides for a certain minimum level of shareholders’ equity and cash, respectively. The aggregate financing provided by the counterparty with respect to the assets covered under this confirmation is approximately $108.8 million and the market value of such assets is approximately $182.7 million. Investment and Leverage As of April 30, 2020, the Company further reduced repurchase agreement financings by selling approximately $370.3 million Agency MBS, $65.3 million in Non-Agency MBS, $148.6 million in conforming whole loans, and $18.2 million in other securities.